Control system



Jan. 16, 1923. 1,442,053. R. E. DE CAMP.

CONTROL SYSTEM. FILED MAY 12, 1939- 2 SHEETS-SHEET 1- WITNESSES:

fig y f. ZJeC'amp m km ATTORNEY INVENTOR Jan. 16, 1923. 1,442,053. H. E. DE CAMP.

CONTROL SYSTEM. FILED MAY 12, 1919.

2 SHEETS-SHEET 2- WITNESSES:

Ray if 0: (amp ATTORNEY INVENTOR Patented Jan. 16, 1923.

UNITED STATES PATENT OFFICE.

RAY E. DE CAMP, OF WILKINSBURG, PENNSYLVANIA, ASSIGN OR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A. CORPORATION OF PENNSYLVANIA.

CONTROL SYSTEM.

Application filed Kay 12, 1919. Serial No. 296,600.

To all whom it may concern:

Be it known that I, RAY E. DE CAMP, a citizen of the United States, and a, resident of \Vilkinsburg, in the county of Allegheny and State of ennsylvania, have invented a new and useful Improvement in Control Systems, of which the following is a specification.

My invention relates to motor-control systems and particularly to systems similar to those disclosed in a co-pending application by H. D. James, Serial No. 236,937, filed May 27, 1918, and assigned to the 'estinghouse Electric & Manufacturing Company, in which the accelerating resistor is adapted to be short-circuited by contactors that are operable upon theclosing of relay members which are under the control of a coil connected across the accelerating resistor, which coil initially actuates a mainrelay armature, and it has for its objectthe provision of an improved accelerating system of this character.

As the resistor, and, therefore, also the coil, becomes ultimately short-circuited, provision must be made for replacing the influence of this coil by some other influence and this is eflected, in the above-mentioned James application, by energizing another coil upon the. short-circuiting of they resistor.

According to the present invention, the second-named coil performs an additional function in that it serves to aid the firstnamed coil to effect the initial operation of the main relay armature, after which the second-named coil becomes de-energized tus embodying one form of m and remains so until the end of the accelerati'ng operation. The second-named coil becomes thereupon again ener ized to maintain the main armature closes.

M invention will, be made clear in connection with the accompanying drawings in which Figs. 1, 2 and 3 are, respectively, a side and an end elevation and a lan view of a relay of the type 'illustra-:d 111- my copending application, Serial No. 241,259, filed June 21, 1918, .and which is of particular'v'alue in a system arran%d according to the present invention. i 4 is a diagrammatic view of circuits apparainvention, and Fig. 5 is a similar view 0 a modifica- As my invention is of particular value in connection with a system employing my above-referred-to relay, illustrated in Figs.

1 to 3, it will conduce to clearness to describe this relay first.

An insulating panel 29 carries two-brackets 30 and 31 supporting coils 22 and 23 which, when energized by current flowing through them create magnetic fields for attracting an armature 32 and any desired number of'additional armatures 33, 34 and 35. A compression spring 36 is adjustably mounted upon a nonmagnetizable rod 37, slidably mounted in projections 38 and 39, which are rigidly connected to, or constitute integral parts of, the bracket 31. The projection 38 serves also as a pole piece for the armature 32, and the projection 39 as a pole piece for the armatures 33, 34 and 35. A bar 40 is rigidly connected to the rod 37 and normally engages the armatures 33, 34 and 35. The spring 36 ,thus normall maintains the armatures 33, 34 and 35 in their open positions, with the members 41, which are carried by these armatures, in contact with the pole piece 39. The members 41 are preferably of nonmagnetizable material to prevent freezing.

The armature 32 is provided with brackets 42, which are pivotally mounted upon the bracket 30, and is normally maintained in contact with one end of the rod 37 by a weak spring 43. The bracket 30 supports a nonmagnetizable U-shaped member 44 between the .arms of which are pivotally mounted the armatures 33, 34 and 35, which carry, respectively, the movable contact members 45, 46 and 47 of relay members 25, 26 and-27. The corresponding stationary contact members 48, 49 and 50 are mounted upon the insulating panel 29. v

Springs 51 are attached to longitudlnall adjustable members 52 and to the other en 5 of the members 41. The pole piece 39 is provided with longitudinally adjustablemembers 53 to regulate air gaps 70 between these members and the corresponding armatures. By means of this adjustment, or by means 0 the members 52, which control the tension of the springs 51, the action of the. magnetic flux produced b the coils 22' and 23 may be so regulated t at the arma.-

tures 33, 34 and 35 will be operated in proper sequence.

that are mounted upon theinsulating panel 29. As shown in Fig. 1, the switch members and 56 are closed and the switch members 55 and 57 are open when the armature 32 occupies its open position and, conversely, when the armature 32 occupies its closed position. e I

- The operation may be briefly described as follows: Upon current flowing through the coil 22, a magnetic field is created which causes the armature 32 to be attracted toward the pole piece 38. The force of the spring 36 is thereupon overcome. and the bar 40 is moved out of engagement with the armatures 33, 34 and 35, the stop members -11 of which are. nevertheless, maintained in engagement with the pole piece 39 until the flux of the magnetic field becomes successively suificiently low to permit the springs 51 to successively actuate the movable contact members 45, 46 and 47, thereby to close the relay members 25, 26 and 27. In the event that the magnetic field becomes too weak to hold the armature 32 in its elevated position, the spring 36, becoming released; will separate the movable from the stationary contact members. Actuation of the armature 32, of course, effects corresponding actuation of the switch member I shall now describe the invention illustrated in Fig. 4, wherein a motor is shown, having an armature 1 and a shunt. field-magnet winding 2, connected between line conductors 3 andA by a contactor 5 having an energizing coil 8, with an accelerating resistor 6 in series with the armature 1. Contactors 10. 11 and 12 are adapted to efiect the short-circuiting of sections 13, 14'and 15 of the resistor 6. The contactors' 10, 11 and 12 are respectively provided with actuating coils 19, 20 and 21. The coil 22 is connected across the resistor 6 at the junction points 79 and. 80 and the coil 23 is connected, at one end, to the junction point 7 9 through the switch members 55 and 56 and, at the other end, to the junction pointe80. When the switch members 55 and 56 are open and the switch members 55 and 57 closed, the coil 23 is'connected in a circuit extending from the line conductor 3, by a conductor 28, through the relay 27, a resistor 24, the switch members 55 and 57 and the coil 23, to the junction point 80, thereby maintaining 'the armature 32 in actuated position following the de-energization of the coil 20. The motor is adapted to be started upon operation of a start push-button switch which initially effects the closing of the circuit of the coil 8. Upon the consequent closing of the contactor 5, a switch 66 mechanicall connected thereto establishes a holding cirupon closed and the start push-button switch may be released, as a holding circuit is established for the coil 8 from the line con-- ductor 3, through the stop push-button switch, the switch 66 and the coil 8 to the line conductor 4. The motor circuit is esf tablished from the line conductor 3, through the contactor 5, the armature 1 and the resistor 6 to the line conductor 4. A circuit is established also for the shunt field-magnet winding 2 in parallel with the armature 1. The coil 22 becomes energized in accordance with the drop in voltage between the junction points 79-and 80 across the resistor 6. Acircuit is established also from the line conductor 3, through the contactor 5, the armature 1, the junction point 79, the contact members 55 and 56, the coil 23 and the junction point- 80, to the line conductor 4. Initially, therefore,-the coils 22 and 23 are both energized in accordance with the drop in voltage across the resistor 6 so that an abnormally large force is exerted upon the armature 32 to effect its actuation into contact with the pole piece 38. Upon such an tuation. of course, contact is broken between the switch members 55 and 56, so that the coil 23 becomes de-energized, the coil 22 32 in contact with the pole piece 38 and the armatures' 33, 34 and 35 in contact with the polepiece 39 (Fig. 1). When the motor attains a predetermined speed, so that the drop in voltage between the points 79 and 80 falls to a predetermined value, the spring 51, which is connected to the armature 33. will effect the actuation of this armature, in opposition to the force of the coil 22, thereby effecting the closing of the relay member 25. A circuit is thus established from the line conductor 3, through the contactor 5, by the conductor 28, through the relay member 25 and the coil 19 to the line conductor 4. The contactor 10 is thereupon closed by its actuating coil- 19 to efl'ect the short-circuiting of the resistor section 13. In similar fashion,

the contactors 11 and 12 will ultimately be closed, in accordance with the value of the voltagedifl'erence between the points '79 and 80, to efi'ectthe short-circuiting of the re I Upon the short-circuiting of the last resistor section comes tie-energized but simultaneously with the energization of the coil 21, following the closing of the relay member 27, the above-traced circuit of the coil 23 through the relay 2,7 and the resistor 24 becomes established, whereby the coil 23 is enabled to maintain the armature 32 in engagement with the pole piece 38 so that the armatures 33, 34 and 35 are maintained free from the influence of the bar 40. The relay members 25,26 and 27, in consequence, are maintained closed to maintain the coils 19, 20, 21 and 23 energized.

According to my invention, therefore, the two coils 22 and 23 initially operate together to effect the actuation of the armature 32. As soon as this armature becomes actuated, the coil 23 becomes de-energized, the accelerating operation being thereafter governed by the coil 22 alone. Ultimately, upon the de-energization of this coil 22, the coil 23 becomes again energized to maintain the armature 32 in its actuated position, so that the motor may continue to operate at the desired speed, with the resistor 6 short-circuited.

The system of Fig. 5 difiers from that of Fig. 4 in that, upon the closing of the relay member 27,the coils 21 and 23,instead-of being connected in parallel, as in the s stem of Fig. 4:, are connected in series. or some purposes this connection is advantageous.

, It will be clear that changes maytbe made in the systems illustrated without in any way departing from the spirit and scope of my invention, as defined in the appended claims.

I claim as my invention:

1. The combination with anelectric motor having a resistor associated therewith and aswitch for short-circuiting said resistor, of an armature for controlling said switch and two coils for controlling said armature, said armature having a double- 15, the coil 22, of course, be

throw switch mechanically connected theretofor controlling the circuit of one of said C01 s. I

2. The combination withhan electric motor and a controlling switch therefor having a pair of controlling coils, of means for ini tially energizing both of said coils, then de-energizing one of said coils, and finally de-energizing the other of said coils and againBenergizing said one coil. 3. The combination with an electric motor having an armature, a resistor in series therewith, and a switch for short-circuiting said resistor having a coil connected across said resistor and a maintaining coil, of

means for initially energizing both of said coils, later de-energizing said maintaining coil, andthen again energizing said maintalnlng coil.

4. The combination with an electric moreslstor in series tor having an armature, a therewith, a plurality of switches forshortcircuiting said resistor, a normally open relay member for each of said switches, an armature for controlling said relay members, a coil connected across said resistor for controlling said relay members and said armature, and a second coil for controlling said armature'uponthe short-circuiting of said resistor, of means controlled by said armature for initially energizing said second coil.

5. The combination with an electric motor having a resistor, a switch for shortcircuitingsaid resistor having an actuating coil and a relay for said switch having a controlling coil initially energized in accordance with the drop in potential across said resistor, of means for connecting said coils in series to be energized in accordance with line voltage'upon the closing of said relay.

In testimony whereof, I have hereunto subscribed my namethis 26th day of April 1919.

RAY E. DE CAMP. 

